What is Chemistry?

Science Others Social Sciences Religion Art Philosophy Literature Ways of gaining knowledge

Physical Science Life Science Environmental Science Physics Chemistry Matter, energy, and their relation. is the heart of science because it studies matter, its composition, and its changes. Science is then a way of gaining knowledge

Chemistry: is the study of matter, its composition, and the changes it undergoes. “You and all the objects around you are composed of matter. By studying matter and the way it changes, you will gain and understanding of your body and all the “stuff” you see and interact within your everyday life. Chemistry, matter and change, Glencoe, 2002

Mass : is the amount of material. Mass is what gives an object the properties of weight and inertia. Energy: The ability to cause changes in matter Weight : is a force and is due to the pull of gravity on the object. Matter is anything that has mass and occupies space.

BranchArea of emphasis Organic ChemistryMost carbon-containing chemicals Inorganic ChemistryIn general, matter that does not contain carbon. Physical ChemistryDeals with the mechanism (how), the rate (speed) and the energy transfer that occur in changes of matter. Analytical ChemistryComponents and composition of substances. BiochemistryMatter and processes of living organisms. Theoretical ChemistryWhy and how chemicals interact. Environmental Chem.The role chemicals play in the environment. Branches of Chemistry

Pure Research: seeks to gain knowledge for the sake of knowledge itself. Ex: the study of the cell. Applied Research: Is research that is directed towards a practical goal or application. It is usually undertaken to solve a specific problem. Ex: the study of the effect of chemotherapy on healthy cells. Types of Scientific Investigations

Some great discoveries have been made by accident, unexpectedly. Do you know the word for that? SERENDIPITY “Serendipity is the effect by which one accidentally discovers something fortunate, especially while looking for something else entirely.” For example the discovery of vulcanization by Charles Goodyear Technology: Is the practical use of scientific information, which is concerned with making improvements in human life and the world around us. Ex: the development of synthetic fibers or the use of aspirin to prevent heart attacks. Types of Scientific Investigations

Chemistry can be useful in explaining the natural world, preparing people for career opportunities and producing informed citizens.. Why study Chemistry?

What is this matter that I have?. Chemists observe and measure properties of matter and the way matter changes to answer these questions. How much (of this matter) do I have? How can I change it (matter)? How much (matter) can I get and how fast? Chemists try to answer 4 basic questions

The word Chemistry comes from Alchemy. ALCHEMISTS: were the first to study matter, even since 400 BC had a practical side and a mystical side developed techniques to work with metals, glass and dyes and in general with chemicals (practical) focused on concepts like perfection (mystical) were searching for ways to change other metals into gold which was considered the perfect metal developed processes to separate mixtures and purifying chemicals they designed equipment that we still use today like beakers, flasks, tongs, funnels and the mortar and pestle did not provide a logical set of explanations for the changes in matter that they observed. Thinking like a scientist

A scientific method: is a systematic approach used in scientific study is an organized process to do research provides a method for scientists to verify the work of others We can describe some steps of this scientific approach, but it is important to realize that each scientist may not follow them exactly or in a specific order. Therefore they must describe the exact procedure followed. The validity of the results must be confirmed by other scientists, following the described procedure. The Scientific Method

Scientific Method

What do you observe in this diagram? The Scientific Method – Some Definitions -- a group of dark dots -- dots of different sizes -- dots of different shapes -- a white background -- more concentration of dots in some areas Observations: Inferences: It may be a Dalmatian: -- sniffing the ground -- or drinking water -- many leaves on the ground -- or many rocks

Observation: What you perceive with your senses, qualitative data, or using tools (measurements), quantitative data. Inference: An interpretation of an observation. Examples: Classify the following as observations or inferences: It is very cloudy It is going to rain The boy is sad The boy is crying The student is looking at an open book The student is reading The Scientific Method – Some Definitions

Background Information: Before starting your investigation on a topic you like, you must find what is already known about the topic. You observe and infer first. Then you research in books, encyclopedia, magazines, your computer, talking to experts, etc… The summary of this knowledge is your background information and must be the base that supports your hypothesis. Hypothesis: A proposed explanation for an observation. Things as they might be. An educated guess. Experiment: A set of controlled observations that test the hypothesis. The Scientific Method – Some Definitions

Variable: A quantity or condition that can have more than one value. Independent Variable: The variable that you plan to change (manipulated variable). Dependent Variable: The variable that changes in response to a change in the independent variable (responding variable). Controlled variables: (Constant) Variables that you control so they don’t affect the results. Control: a standard for comparison. It may be an extra set up or just a color to compare etc. The Scientific Method – Some Definitions

Conclusion: A judgment based on the information obtained Theory: An attempt to explain why something happens. Is a well-tested explanation for a broad set of observations. Scientific Law: Summarizes the results of many observations and experiments. The formulation of an observed behavior. It is a relationship in nature that has been supported by many experiments. The Scientific Method – More definitions

The Scientific Method- Practice Suppose you need to design an experiment to test the hypothesis that table salt dissolves faster in hot water than in water at room temperature(20˚C). What are your variables? Independent: Dependent: Control: Controlled Variables (constant variables): The Experimental Method: Temperature The rate at which it dissolves Water at room temperature the amount of salt, the amount of water, the stirring of the solution.

Model: A representation. A theory in the form of a picture or idea about something that cannot be viewed directly. It can also be defined as a visual, verbal and/or mathematical explanation of experimental data. Collaboration and communication When scientists collaborate and communicate they increase the likelihood of a successful outcome. The Scientific Method – More definitions